scholarly journals Distribution of ε-Poly-L-Lysine Synthetases in Coryneform Bacteria Isolated from Cheese and Human Skin

2021 ◽  
Vol 87 (10) ◽  
Author(s):  
Xinglin Jiang ◽  
Yulia Radko ◽  
Tetiana Gren ◽  
Emilia Palazzotto ◽  
Tue Sparholt Jørgensen ◽  
...  
Keyword(s):  
Human Skin ◽  
Wide Spectrum ◽  
Streptomyces Coelicolor ◽  
Domain Architecture ◽  
Food Preservation ◽  
Food Component ◽  
Content Type ◽  
Skin Bacteria ◽  
Antibiotic Drugs ◽  
Bioactive Secondary Metabolite

ABSTRACT ε-Poly-l-lysine is a potent antimicrobial produced through fermentation of Streptomyces and used in many Asian countries as a food preservative. It is synthesized and excreted by a special nonribosomal peptide synthetase (NRPS)-like enzyme called Pls. In this study, we discovered a gene from cheese bacterium Corynebacterium variabile that showed high similarity to the Pls from Streptomyces in terms of domain architecture and gene context. By cloning it into Streptomyces coelicolor with a Streptomyces albulus Pls promoter, we confirmed that its product is indeed ε-poly-l-lysine. A comprehensive sequence analysis suggested that Pls genes are widely spread among coryneform actinobacteria isolated from cheese and human skin; 14 out of 15 Brevibacterium isolates and 10 out of 12 Corynebacterium isolates contain it in their genomes. This finding raises the possibility that ε-poly-l-lysine as a bioactive secondary metabolite might be produced and play a role in the cheese and skin ecosystems. IMPORTANCE Every year, microbial contamination causes billions of tons of food wasted and millions of cases of illness. ε-Poly-l-lysine has potent, wide-spectrum inhibitory activity and is heat stable and biodegradable. It has been approved for food preservation by an increasing number of countries. ε-Poly-l-lysine is produced from soil bacteria of the genus Streptomyces, also producers of various antibiotic drugs and toxins and not considered to be a naturally occurring food component. The frequent finding of pls in cheese and skin bacteria suggests that ε-poly-l-lysine may naturally exist in cheese and on our skin, and ε-poly-l-lysine producers are not limited to filamentous actinobacteria.

scholarly journals Distribution of Epsilon-Polylysine Synthetases in Coryneform Bacteria Isolated from Cheese and Human Skin

2020 ◽  
Author(s):  
Xinglin Jiang ◽  
Yulia Radko ◽  
Tetiana Gren ◽  
Emilia Palazzotto ◽  
Tue Sparholt Jørgensen ◽  
...  
Keyword(s):  
Human Skin ◽  
Wide Spectrum ◽  
Streptomyces Coelicolor ◽  
Domain Architecture ◽  
Food Preservation ◽  
Unexpected Finding ◽  
Coryneform Bacteria ◽  
Skin Bacteria ◽  
Antibiotic Drugs ◽  
Bioactive Secondary Metabolite

ABSTRACTEpsilon-polylysine (ε-PL) is an antimicrobial commercially produced by Streptomyces fermentation and widely used in Asian countries for food preservation. Here we discovered a gene from cheese bacterium Corynebacterium variabile that showed high similarity to the ε-PL synthetase from Streptomyces in terms of enzymatic domain architecture and gene context. By cloning it into Streptomyces coelicolor with a Streptomyces albulus ε-PL synthetase promoter, we confirmed that its product is indeed ε-PL. A comprehensive sequence analysis suggests that ε-PL synthetases are widely spread among coryneform bacteria isolated from cheese and human skin; 14 out of 15 Brevibacterium isolates and 10 out of 12 Corynebacterium isolates contain Pls gene. This discovery raises the possibility that ε-PL as a bioactive secondary metabolite might be produced and play a role in the cheese and skin ecosystems.IMPORTANCEEvery year, microbial contamination causes billions of tons of food wasted and millions of cases of foodborne illness. ε-PL is an excellent food preservative as it is potent, wide spectrum and is heat stable and biodegradable. It has not been accepted by all countries (e.g those in the EU) partially because it was not a natural composition of food but rather originated from the soil bacteria Streptomyces, a famous producer of various antibiotic drugs and toxins. The unexpected finding of ε-PL synthetases in cheese and skin bacteria suggests that ε-PL may naturally exist in cheese and on our skin.

scholarly journals Complete Genome Sequence of Malassezia restricta CBS 7877, an Opportunist Pathogen Involved in Dandruff and Seborrheic Dermatitis

2019 ◽  
Vol 8 (6) ◽  
Author(s):  
Stanislas C. Morand ◽  
Morgane Bertignac ◽  
Agnes Iltis ◽  
Iris C. R. M. Kolder ◽  
Walter Pirovano ◽  
...  
Keyword(s):  
Human Skin ◽  
Genome Sequence ◽  
Complete Genome Sequence ◽  
Complete Genome ◽  
Seborrheic Dermatitis ◽  
Skin Microbiome ◽  
Basidiomycetous Yeasts ◽  
Content Type ◽  
Opportunist Pathogen ◽  
Malassezia Restricta

Malassezia restricta, one of the predominant basidiomycetous yeasts present on human skin, is involved in scalp disorders. Here, we report the complete genome sequence of the lipophilic Malassezia restricta CBS 7877 strain, which will facilitate the study of the mechanisms underlying its commensal and pathogenic roles within the skin microbiome.

scholarly journals In VivoStudies Suggest that Induction of VanS-Dependent Vancomycin Resistance Requires Binding of the Drug to d-Ala-d-Ala Termini in the Peptidoglycan Cell Wall

2013 ◽  
Vol 57 (9) ◽  
pp. 4470-4480 ◽  
Author(s):  
Min Jung Kwun ◽  
Gabriela Novotna ◽  
Andrew R. Hesketh ◽  
Lionel Hill ◽  
Hee-Jeon Hong
Keyword(s):  
Cell Wall ◽  
Transcriptional Activation ◽  
Streptomyces Coelicolor ◽  
Constitutive Expression ◽  
Transcriptional Response ◽  
Vancomycin Resistance ◽  
Content Type ◽  
Expression Of Genes ◽  
Peptidoglycan Cell Wall

ABSTRACTVanRS two-component regulatory systems are key elements required for the transcriptional activation of inducible vancomycin resistance genes in bacteria, but the precise nature of the ligand signal that activates these systems has remained undefined. Using the resistance system inStreptomyces coelicoloras a model, we have undertaken a series ofin vivostudies which indicate that the VanS sensor kinase in VanB-type resistance systems is activated by vancomycin in complex with thed-alanyl-d-alanine (d-Ala-d-Ala) termini of cell wall peptidoglycan (PG) precursors. Complementation of an essentiald-Ala-d-Ala ligase activity by constitutive expression ofvanAencoding a bifunctionald-Ala-d-Ala andd-alanyl-d-lactate (d-Ala-d-Lac) ligase activity allowed construction of strains that synthesized variable amounts of PG precursors containingd-Ala-d-Ala. Assays quantifying the expression of genes under VanRS control showed that the response to vancomycin in these strains correlated with the abundance ofd-Ala-d-Ala-containing PG precursors; strains producing a lower proportion of PG precursors terminating ind-Ala-d-Ala consistently exhibited a lower response to vancomycin. Pretreatment of wild-type cells with vancomycin or teicoplanin to saturate and mask thed-Ala-d-Ala binding sites in nascent PG also blocked the transcriptional response to subsequent vancomycin exposure, and desleucyl vancomycin, a vancomycin analogue incapable of interacting withd-Ala-d-Ala residues, failed to inducevangene expression. Activation of resistance by a vancomycin–d-Ala-d-Ala PG complex predicts a limit to the proportion of PG that can be derived from precursors terminating ind-Ala-d-Lac, a restriction also enforced by the bifunctional activity of the VanA ligase.

Using consumer surveys to determine food sustainability

2014 ◽  
Vol 116 (7) ◽  
pp. 1194-1204 ◽  
Author(s):  
Wayne Martindale
Keyword(s):  
Food Service ◽  
Food Preservation ◽  
Frozen Foods ◽  
Content Type ◽  
Frozen Food ◽  
Product Categories ◽  
Fresh Food ◽  
Consumer Surveys ◽  
Meal Planning ◽  
Assess Quality

Purpose – The purpose of this paper is to define the sustainability attributes of frozen and fresh food consumption in a typical household. The reason for writing this paper is that food preservation is often overlooked when developing sustainability strategies. Design/methodology/approach – This study uses established carbon footprint data for specific food types and consumer survey data to determine how consumers use fresh and frozen products in the home. Consumption and waste data for 83 households was obtained using a combination of narrative and graphical association questions. Findings – The results show greenhouse gas emissions associated with a diets containing frozen food are reduced because 47 per cent less frozen foods is wasted as compared to fresh foods with a typical household wasting 10.4 per cent of fresh food and 5.9 per cent frozen food. Research limitations/implications – This research has highlighted the importance of understanding the waste impacts of catering and food service consumption outside the home. Practical implications – This research will guide future product development for frozen foods with regard to dietary planning and portion control. Social implications – The cost and sustainability benefits of meal planning are identified and these will inform policy making and education to improve dietary choices. Originality/value – This work extends the scope of current consumer surveys that assess quality, value and taste attributes to sustainability criteria and it will enable collaboration between fresh and frozen product categories to deliver sustainable dietary options.

Two-dimensional thermo-mechanical fractional responses to biological tissue with rheological properties

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Magdy A. Ezzat ◽  
Roland W. Lewis
Keyword(s):  
Rheological Properties ◽  
Human Skin ◽  
Fractional Order ◽  
Order Parameters ◽  
Bioheat Transfer ◽  
Skin Tissue ◽  
Two Dimensional ◽  
Volume Relaxation ◽  
Content Type ◽  
Human Skin Tissue

Purpose The system of equations for fractional thermo-viscoelasticity is used to investigate two-dimensional bioheat transfer and heat-induced mechanical response in human skin tissue with rheological properties. Design/methodology/approach Laplace and Fourier’s transformations are used. The resulting formulation is applied to human skin tissue subjected to regional hyperthermia therapy for cancer treatment. The inversion process for Fourier and Laplace transforms is carried out using a numerical method based on Fourier series expansions. Findings Comparisons are made with the results anticipated through the coupled and generalized theories. The influences of volume materials properties and fractional order parameters for all the regarded fields are examined. The results indicate that volume relaxation parameters, as well as fractional order parameters, play a major role in all considered distributions. Originality/value Bio-thermo-mechanics includes bioheat transfer, biomechanics, burn injury and physiology. In clinical applications, knowledge of bio-thermo-mechanics in living tissues is very important. One can infer from the numerical results that, with a finite distance, the thermo-mechanical waves spread to skin tissue, removing the unrealistic predictions of the Pennes’ model.

scholarly journals Regulation of Sporangium Formation by BldD in the Rare Actinomycete Actinoplanes missouriensis

2017 ◽  
Vol 199 (12) ◽  
Author(s):  
Yoshihiro Mouri ◽  
Kenji Konishi ◽  
Azusa Fujita ◽  
Takeaki Tezuka ◽  
Yasuo Ohnishi
Keyword(s):  
Vegetative Growth ◽  
Streptomyces Coelicolor ◽  
Morphological Differentiation ◽  
Transcriptional Regulator ◽  
Saccharopolyspora Erythraea ◽  
Transcriptional Analysis ◽  
Morphological Development ◽  
Sequencing Analysis ◽  
Content Type ◽  
Biological Studies

ABSTRACT The rare actinomycete Actinoplanes missouriensis forms sporangia, including hundreds of flagellated spores that start swimming as zoospores after their release. Under conditions suitable for vegetative growth, zoospores stop swimming and germinate. A comparative proteome analysis between zoospores and germinating cells identified 15 proteins that were produced in larger amounts in germinating cells. They include an orthologue of BldD (herein named AmBldD [BldD of A. missouriensis]), which is a transcriptional regulator involved in morphological development and secondary metabolism in Streptomyces. AmBldD was detected in mycelia during vegetative growth but was barely detected in mycelia during the sporangium-forming phase, in spite of the constant transcription of AmbldD throughout growth. An AmbldD mutant started to form sporangia much earlier than the wild-type strain, and the resulting sporangia were morphologically abnormal. Recombinant AmBldD bound a palindromic sequence, the AmBldD box, located upstream from AmbldD. 3′,5′-Cyclic di-GMP significantly enhanced the in vitro DNA-binding ability of AmBldD. A chromatin immunoprecipitation-sequencing analysis and an in silico search for AmBldD boxes revealed that AmBldD bound 346 genomic loci that contained the 19-bp inverted repeat 5′-NN(G/A)TNACN(C/G)N(G/C)NGTNA(C/T)NN-3′ as the consensus AmBldD-binding sequence. The transcriptional analysis of 27 selected AmBldD target gene candidates indicated that AmBldD should repress 12 of the 27 genes, including bldM, ssgB, whiD, ddbA, and wblA orthologues. These genes are involved in morphological development in Streptomyces coelicolor A3(2). Thus, AmBldD is a global transcriptional regulator that seems to repress the transcription of tens of genes during vegetative growth, some of which are likely to be required for sporangium formation. IMPORTANCE The rare actinomycete Actinoplanes missouriensis undergoes complex morphological differentiation, including sporangium formation. However, almost no molecular biological studies have been conducted on this bacterium. BldD is a key global regulator involved in the morphological development of streptomycetes. BldD orthologues are highly conserved among sporulating actinomycetes, but no BldD orthologues, except one in Saccharopolyspora erythraea, have been studied outside the streptomycetes. Here, it was revealed that the BldD orthologue AmBldD is essential for normal developmental processes in A. missouriensis. The AmBldD regulon seems to be different from the BldD regulon in Streptomyces coelicolor A3(2), but they share four genes that are involved in morphological differentiation in S. coelicolor A3(2).

scholarly journals Population-Wide Survey of Salmonella enterica Response to High-Pressure Processing Reveals a Diversity of Responses and Tolerance Mechanisms

2017 ◽  
Vol 84 (2) ◽  
Author(s):  
Sandeep Tamber
Keyword(s):  
High Pressure ◽  
Foodborne Pathogens ◽  
Salmonella Enterica ◽  
High Pressure Processing ◽  
Food Preservation ◽  
Iodide Uptake ◽  
Membrane Fatty Acid Composition ◽  
Content Type ◽  
Pressure Resistance ◽  
Treatment Sensitivity

ABSTRACTHigh-pressure processing is a nonthermal method of food preservation that uses pressure to inactivate microorganisms. To ensure the effective validation of process parameters, it is important that the design of challenge protocols consider the potential for resistance in a particular species. Herein, the responses of 99 diverseSalmonella entericastrains to high pressure are reported. Members of this population belonged to 24 serovars and were isolated from various Canadian sources over a period of 26 years. When cells were exposed to 600 MPa for 3 min, the average reduction in cell numbers for this population was 5.6 log10CFU/ml, with a range of 0.9 log10CFU/ml to 6 log10CFU/ml. Eleven strains, from 5 serovars, with variable levels of pressure resistance were selected for further study. The membrane characteristics (propidium iodide uptake during and after pressure treatment, sensitivity to membrane-active agents, and membrane fatty acid composition) and responses to stressors (heat, nutrient deprivation, desiccation, and acid) for this panel suggested potential roles for the cell membrane and the RpoS regulon in mediating pressure resistance inS. enterica. The data indicate heterogeneous and multifactorial responses to high pressure that cannot be predicted for individualS. entericastrains.IMPORTANCEThe responses of foodborne pathogens to increasingly popular minimal food decontamination methods are not understood and therefore are difficult to predict. This report shows that the responses ofSalmonella entericastrains to high-pressure processing are diverse. The magnitude of inactivation does not depend on how closely related the strains are or where they were isolated. Moreover, strains that are resistant to high pressure do not behave similarly to other stresses, suggesting that more than one mechanism might be responsible for resistance to high pressure and the mechanisms used may vary from one strain to another.

Learning about translators from library catalog records: implications for readers’ advisory

2015 ◽  
Vol 116 (5/6) ◽  
pp. 264-276
Author(s):  
Keren Dali ◽  
Lana Alsabbagh
Keyword(s):  
Public Libraries ◽  
Wide Spectrum ◽  
Methodological Approach ◽  
Real Life ◽  
Library Catalog ◽  
Content Type ◽  
Bibliographic Records ◽  
Bibliographic Data ◽  
English Speaking ◽  
Public Librarians

Purpose – The purpose of this article is to make public librarians aware of the wealth of information about translators that is contained in bibliographic records of their own library catalogs so they could use this information for the benefit of readers’ advisory (RA) work involving translated titles. Design/methodology/approach – The article uses the method of bibliographic data analysis based on 350 selected translated fiction titles (and 2,100 corresponding catalog records) from six large Canadian public libraries. Findings – As the results demonstrate, enhanced bibliographic catalog records deliver a wide spectrum of information about translators, which can be used by public libraries to provide more informed and insightful reading advice and to make more sensible purchasing decisions with regard to translated fiction. Practical implications – The study shows how the most readily available tool – a library catalog with its enhanced bibliographic records – can be utilized by public librarians for improving RA practices. It focuses on the rarely discussed translated fiction, demonstrates a sample methodological approach and makes suggestions for implementing this approach by busy public librarians in real-life situations. Originality/value – No recent studies that have investigated enhanced catalog records have dealt with translated fiction. Moreover, while authors/writers are often in the focus of RA studies, translators are often left behind the scenes, despite their crucial role in bringing international fiction to English-speaking readers.

scholarly journals d-Limonene: a bioactive food component from citrus and evidence for a potential role in breast cancer prevention and treatment

2011 ◽  
pp. 31-42
Author(s):  
Jessica A. Miller ◽  
Patricia A. Thompson ◽  
Iman A. Hakim ◽  
H.-H. Sherry Chow ◽  
Cynthia A. Thomson
Keyword(s):  
Breast Cancer ◽  
Cancer Prevention ◽  
Immune Modulation ◽  
Wide Spectrum ◽  
Perillyl Alcohol ◽  
Potent Effect ◽  
Food Component ◽  
Citrus Peel ◽  
Anti Cancer ◽  
Prevention And Treatment

Although limited, observations from cell culture, animal, and epidemiological studies support the presence of anti-cancer properties in citrus peel and the primary bioactive food constituent, d-limonene. Early evidence from animal models suggests that when ingested, d-limonene exhibits a wide spectrum of biologic activity including chemotherapeutic and chemopreventive effects. In some of these early models, an analog of d-limonene, perillyl alcohol, demonstrated a more potent effect than d-limonene itself. Yet, when perillyl alcohol advanced to clinical trials, several trials were ended early due to doselimiting toxicities. Alternatively, oral d-limonene administration in humans is well tolerated even at high doses supporting its investigation as a potential bioactive for cancer prevention. Though the exact mechanisms of action of d-limonene are unclear, immune modulation and antiproliferative effects are commonly reported. Here, we review the pre-clinical evidence for d-limonene’s anticancer mechanisms, bioavailability, and safety, as well as the evidence for anti-cancer effects in humans, focusing on studies relevant to its use in the prevention and treatment of breast cancer.

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